This chapter gives an overview of how Cargo comes together, and how you can be a part of that process.
See the Working on Cargo chapter for an overview of the contribution process.
Please read the guidelines below before working on an issue or new feature.
Due to limited review capacity, the Cargo team is not accepting new features or major changes at this time. Please consult with the team before opening a new PR. Only issues that have been explicitly marked as accepted will be reviewed.
Cargo is managed by a team of volunteers. The Cargo Team reviews all changes, and sets the direction for the project.
The team meets on a weekly basis on a video chat. If you are interested in participating, feel free to contact us on Zulip.
The Roadmap Project Board is used for tracking major initiatives. This gives an overview of the things the team is interested in and thinking about.
The RFC Project Board is used for tracking RFCs.
Working on small bugs
Issues labeled with the E-help-wanted, E-easy, or E-mentor labels are typically issues that the Cargo team wants to see addressed, and are relatively easy to get started with. If you are interested in one of those, and it has not already been assigned to someone, leave a comment. See Issue assignment below for assigning yourself.
If there is a specific issue that you are interested in, but it doesn’t have
one of the
E- labels, leave a comment on the issue. If a Cargo team member
has the time to help out, they will respond to help with the next steps.
Working on large bugs
Some issues may be difficult to fix. They may require significant code changes, or major design decisions. The E-medium and E-hard labels can be used to tag such issues. These will typically involve some discussion with the Cargo team on how to tackle it.
Working on small features
Small feature requests are typically managed on the issue tracker. Features that the Cargo team have approved will have the Feature accepted label or the E-mentor label. If there is a feature request that you are interested in, feel free to leave a comment expressing your interest. If a Cargo team member has the time to help out, they will respond to help with the next steps. Keep in mind that the Cargo team has limited time, and may not be able to help with every feature request. Most of them require some design work, which can be difficult. Check out the design principles chapter for some guidance.
Working on large features
Cargo follows the Rust model of evolution. Major features usually go through an RFC process. Therefore, before opening a feature request issue create a Pre-RFC thread on the internals forum to get preliminary feedback.
Implementing a feature as a custom subcommand is encouraged as it helps demonstrate the demand for the functionality and is a great way to deliver a working solution faster as it can iterate outside of Cargo’s release cadence.
See the unstable chapter for how new major features are typically implemented.
Bots and infrastructure
The Cargo project uses several bots:
- GitHub Actions are used to automatically run all tests for each PR.
- triagebot automatically assigns reviewers for PRs, see Assignment for how to configure.
- bors is used to merge PRs. See The merging process.
- triagebot is used for assigning issues to non-members, see Issue assignment.
- rfcbot is used for making asynchronous decisions by team members.
Normally, if you plan to work on an issue that has been marked with one of the
E- tags or Feature accepted, it is sufficient just to leave a comment that
you are working on it. We also have a bot that allows you to formally “claim”
an issue by entering the text
@rustbot claim in a comment. See the
Assignment docs on how this works.